My Vsx-52 (purchased dec. 2011) has the same issue. It is a bad HDMI board and must be replaced. Pioneer has been offering a free fix to this ($600) problem. On March 7th 2019 I received approval to have this board replaced at no charge. It must be fixed at their HQ. They are sending me a prepaid shipping box. I will receive it in 7 to 10 business days.
If you haven't already, go to the service section of their website (now onkyo) and send them an email. State that you understand they are offering a fix. For more info, Google UE22 and go to a avform. I followed their expert’s advice and was successful.